Answer to Question #28343 in Mechanics | Relativity for anna
A 50-kilogram student stands in an elevator. How much force does she
exert on the elevator floor if:
a. The elevator is stationary?
If a woman weighs 50 kg and is standing in a motionless elevator, she will exert a force of 50kg onto the elevator floor, which is approximately 490 Newtons. (Net force will be zero, as F=ma. acceleration is zero.)
b. The elevator accelerates upward at 1 meter per second squared
If the elevator is accelerating upward (against the force of gravity), then According to Newton’s second law of motion, the force exerted on the girl (upwards by the elevator floor) must be greater than the force of gravity (pulling her down). If she is moving upwards at a rate of 1m/s/s, then this must be in addition to the downward pull of gravity (9.8m/s/s). Therefore, the upward force of the elevator is 9.8 m/s/s+1m/s/s= 10.8m/s/s, but the acceleration is only 1m/s/s.
490N X 1 m/s/s + 50 = support Force (540N)
is this correct?